This application relates to protective eyewear of the type worn by medical, surgical, dental, and other professionals, and particularly eyewear that allow users to maintain ideal, healthy working posture while simultaneously providing ideal working vision. The terminology “eyewear” includes “eye glasses”, “loupes”, “goggles”, “safety glasses”, “smart glasses”, “protective eyewear”, and other types of wearable devices worn over the eyes.
This application is a continuation-in-part application of the previous patent application with Ser. No. 15/984,383, with the title “ERGONOMIC PROTECTIVE EYEWEAR”, filed by Alexander Shau and Jeng-Jye Shau on May 20, 2018.
Doctors, surgeons, dentists, and other professionals often need to work on a patient or object that requires use of the hands below the normal level of eye sight. FIG. 1(a) illustrates an example of a doctor (111) working on a patient (102) using traditional protective eyewear (112). The Working Declination Angle (WDA) is defined as the angle between the horizontal plane and the line from the viewer's eyes to the working area. Here, the horizontal plane is used to approximate a viewer's unstrained, straight viewing direction while sitting or standing with ergonomically healthy posture. For most people, the Working Declination Angle (WDA) is larger than 45 degrees, and is often larger than 60 degrees. Using traditional protective eyewear (112), the doctor (111) needs to bend the head, neck, or back, and/or use excessive downward eye tilt in order to view the working area clearly, as shown in FIG. 1(a). The doctor (111) frequently needs to hold this uncomfortable and unhealthy posture for long periods of time throughout a working day. Such unfavorable working posture frequently results in back, neck, shoulder, and/or eye strain, causing fatigue that can degrade the quality of the operation and also lead to health problems for the professional.
The most common prior art solution for this problem is to wear specialized eyewear (122) using loupes or magnification eye pieces (124) arranged in an Eyewear Declination Angle (EDA), as illustrated in FIG. 1(b). The Eyewear Declination Angle (EDA) is defined as the angle between the eyewear viewing direction and the viewing direction of the image capturing device(s) on the eyewear, as illustrated by the example in FIG. 1(b). The eyewear viewing direction is defined as the unstrained, straight viewing direction through the eyewear, approximately parallel to the horizontal plane when the user sits or stands with ideal, healthy posture. An image capturing device can be an eye piece, camera, or other optical and/or electronic device. For the case in FIG. 1(b), the eyewear declination angle (EDA) of the magnification eye pieces (124) allows the doctor (121) to view working areas with less bending of the neck and back, as illustrated in FIG. 1(b). However, due to space limitations, the achievable eyewear declination angle (EDA) of the magnification eye pieces (124) is typically limited to be significantly smaller than the working declination angle (WDA). Furthermore, use of such specialized eyewear (122) still requires the user to strain the eyes in a downward direction. It provides a partial solution to the problem, but it does not solve the problem adequately. Professionals are still required to strain the back, neck, shoulders and/or eyes to achieve proper working vision, though to a lesser degree when compared with the traditional protective eyewear in FIG. 1(a).
Chang in U.S. Pat. No. 9,465,235 disclosed a through-the-lens loupe with improved eyewear declination angle. Holes are opened on the viewing windows of the eyewear to allow larger built-in eyewear declination angles. However, the angle is still not large enough to allow the doctor to maintain ideal ergonomic posture while working.
Fante et al. in U.S. Pat. No. 7,542,204 disclosed a method to improve eyewear declination angle using optical deflectors. The resulting microscopes are larger and heavier than the prior art example in FIG. 1(b). Fante may help reduce problems caused by the working declination angle, but the added weight of the deflectors may also cause ergonomic problems.
Fujie et al in U.S. patent application Ser. No. 11/090,820 disclosed a system for dental diagnosis and treatment that includes a camera which can capture moving images in the patient's oral cavity, and the camera can be fixed near the patient's mouth. The image captured by the camera is displayed on a TV screen or monitor installed at a position where the dentist can see. Using video image processing methods, the system can invert the image in the vertical direction and reverse the image in the lateral direction. The capabilities of Fujie's image processing are limited to image reversion. Additionally, the image is taken from a camera directly facing the mouth of a patient, which is not the same position of view from which dentists are familiar with working. Using this system, dentists need to operate with a different field of view from those with which they are trained. Furthermore, images displayed on the monitor are two-dimensional views which lack depth perception. Depth perception is defined as the visual ability to perceive the world in three dimensions, the ability to judge the distance of objects, and the ability to perceive the spatial relationship of objects at different distances. This information is critical for operations requiring precise hand-eye coordination. Fujie may help reduce the ergonomic problems caused by unfavorable posture, but with this system, users need to spend time re-training themselves to operate in an unfamiliar manner.
Garofolo et al in U.S. Pat. No. 9,690,119 disclosed a device that is equivalent to a virtual reality eyewear with an added centered camera system. Images of a working area captured by the centered camera are displayed on the screen of the virtual reality eyewear, allowing the user to view the working area while working with ergonomically healthy posture. However, an optical system relying on a single, centered camera cannot provide three-dimensional views with accurate and realistic depth perception. Garofolo's camera points horizontally forward at vision redirecting mechanisms or mirrors, instead of pointing directly downward at the patient or object. Garofolo relies on these additional vision redirecting mechanisms to view below eye level, and these additional mechanisms add more weight to the device. This increased weight will make the device heavier and less ergonomic. Garofolo's field of view is also limited by the size of his vision redirecting mechanisms. An increase in the size of Garofolo's vision redirecting mechanisms or mirrors would increase the field of view, but again, such a size increase would simultaneously add unnecessary weight and volume to the eyewear. These limitations significantly hinder Garofolo's ability to support professional operations that require precise hand-eye coordination.
Borenstein in US Patent Application publication number 2016/0104453 disclosed cameras that are embedded in front of the lenses of an eyewear, and these cameras point in a forward direction to enhance what the user can already see with his/her own eyes. Borenstein's cameras point forward, instead of pointing downward with an adjustable declination angle. Because of this critical structure difference, Borenstein's cameras are not useful in solving the aforementioned ergonomic problem faced by dentists, doctors and other professionals. Borenstein does not allow such professionals to see objects or patients at a large working declination angle without elimination or minimization of neck, back, shoulder, or eye strain.
These prior art devices provide partial solutions to the problem, but they do not solve the problem adequately. It is therefore desirable to provide eyewear for medical, surgical, dental, and other professionals that can allow the user to work from his/her trained working positions, while simultaneously operating with ideal ergonomic posture. Trained working positions are the user's physical positions relative to the working area, while the user is performing work on the working area, from which the majority of people in the user's profession have been trained. The working area can be a patient, surface or object(s). For example, most right-handed dentists have been trained to perform dentistry while positioned in the 7 to 1 o'clock positions relative to the patient's head. As another example, most left-handed dentists have been trained to perform dentistry while positioned in the 11 to 5 o'clock positions relative to the patient's head. It is also essential that the eyewear can provide accurate three-dimensional views with realistic and natural depth perception, from the user's trained working positions. It is additionally essential that the eyewear can provide additional working aids using image processing technology and audio signal processing technology. Other professionals who are required to work below a horizontal level of eye sight, such as dental hygienists, veterinarians, laboratory technicians, and jewelers, will also benefit from this invention.